Sudden infant death syndrome (SIDS)
is defined as the sudden and unexpected death of an apparently healthy
infant. A thorough history and postmortem examination are typically
insufficient to explain the cause of death. It is an affliction that
has been recognized since biblical times.

Increasing the Breast-Feeding Rates

Recent well-controlled studies
have consistently shown that infants who were never breast-fed were
two or three times more likely to die of SIDS than their breast-fed
counterparts. Because of its high content of immunoglobulins and other
antibacterial agents, breast milk has also been shown to have protective
effects against illnesses such as rotavirus infections, ear infections,
and upper and lower respiratory tract infections. It is not clear
why breast-feeding is protective against SIDS. Gordon et al have speculated
that the protective effect of breast milk could in part be attributable
to the binding effects of IgA on bacterial toxins, such as staphylococcal
enterotoxin C and Clostridium perfringens enterotoxin A, implicated in
some cases of SIDS. Because breast-fed infants are usually healthier
than their bottle-fed counterparts, they also tend to be resistant
to whatever causes SIDS. Another possible explanation could be that, because
of its richness in long-chain polyunsaturated fatty acids and other nutrients,
breast milk enhances faster development of the central nervous system
of the infants. Also, the frequent tactile stimulation of breast-feeding
during the night may actually protect against SIDS.

Nationally, about 60% of new mothers
initiate breast-feeding, though only about 25% continue to do so 6 months
after delivery. These figures vary widely depending on the region; they
are highest in the Northeast and lowest in the Southeast. These rates
are consistently lower among ethnic minorities than whites. In rural Mississippi,
a recent survey showed that breast-feeding initiation rates were only
19% for blacks versus 44% for whites. Breast-feeding rates 6 months after
delivery were not measured but were likely to have been substantially
lower. Increasing the breast-feeding rates in the Delta region of Mississippi
would necessitate educating and encouraging new mothers to breast-feed
their infants.

Breast-feeding education programs
should preferably be initiated before delivery, and efforts should be
continued after delivery. Some studies have shown that most breast-feeding
counseling is done by allied health care workers. Physicians often report
being inadequately prepared for the task during residency training. Physicians,
nurses, nutritionists, and other health care professionals should therefore
all be involved in such programs. For the programs to be effective, educational
programs should involve not only mothers, but also husbands, friends,
family members, and significant others. Other studies also show that social
support systems, such as those at the workplace and in the hospitals,
are necessary for a successful breast-feeding program.

Conclusion Sudden infant death syndrome is the single most important cause of
postneonatal mortality in the United States. In the Delta region of
Mississippi, we recommend a three-pronged educational approach to reduce
the incidence of SIDS in this region: (1) increasing the proportion of
infants sleeping in the nonprone position, (2) decreasing the proportion
of young infants exposed to passive smoke in homes, and (3) increasing
the proportion of mothers initiating breast-feeding and continuing to
breast-feed for at least 12 months after delivery. Until the cause
of SIDS is found, our only hope of combating this endemic problem is through
lasting changes in infant care practices in our community. Other factors,
such as type of bedding, cosleeping, long QT syndrome, and ambient room
temperature, may also be of some importance but, for now, too much emphasis
on these may only add to parents' confusion. We believe that the three
factors discussed in this paper are the most important, and health education
programs focused on them will dramatically decrease the incidence of SIDS
in this community.

Sudden Infant Death Syndrome (SIDS),
the leading cause of infant death from one to six months in the developed
world, strikes approximately two infants per 1000 live births
in the U.S. The characteristics of the infants who die suddenly and unexpectedly
are non-specific; none are universal except for the age distribution.
Therefore, an infant is recognized to have died from SIDS only after thorough
examination fails to demonstrate any other cause for the death. It is
the purpose of this paper to review the most populat hypotheses of the
causes of SIDS and try to explain through published scientific findings
how breastfed infants appear to be protected from this condition.
Many hypotheses have been proposed to explain SIDS. Some deficiencies/problems
are related to the infant, such as a defect in sleep and/or breathing
control, severe infant botulism, infections, reactions to immunizations,hypersensitivity to cow's milk, "maternal deprivation syndrome."
Other causes are attributed to maternal circumstances, such as lower socioeconomic
status, prenatal health, smoking, and the winter season. Additional suggestions
of potential causes of SIDS include baby's thiamine deficiency, and hormonal
and/or biochemical imbalance. The occurrence of most of these circumstances
can be associated with a lack of breastfeeding. Because SIDS occurs
much less frequently in breastfed infants, it is speculated that breastfeeding
protects infants against SIDS. However, scientific literature lacks uniformity
in the definitions of breastfeeding (whether partial and exclusive). This
specification is necessary to select control infants to elucidate the
well documented substantial lower rate of incidence of SIDS in breastfed
babies.

There are many etiopathogenetic
theories that hypothesize several causes or factors supporting the onset
of Sudden Infant Death Syndrome (SIDS). Among the SIDS factors there are
bacterial endotoxins which can be conveyed into the organism in large
amounts, by contaminated milk. An epidemiologic research was carried out
on a sample of 258 mothers of children and boys attending some schools
of L'Aquila district in 1988. It supplied data on the nursing procedures
and about diseases with unknown aetiology related to nursing periods.
The results obtained refer to the years 1974-84: 33.6% of sample was normal
breast-fed infants. We found increasing percentage values referred to
bottle-fed infants the first month of life (45% of sample in 1984); 22.5%
of sample was bottle-fed infants only. Cows' milk was less and less used
and it reached the 5% value in 1984. A case of hypothetic near-SIDS (0.4%)
was found and another case which can be defined at SIDS-risk. It concerns
two bottle-fed infants whose milk was diluted with simple drinking water.
In addition a case of SIDS in a family was found: she was a girl aged
23 weeks who had begun drinking neat cows' milk only twenty days before
the disease.

Approximately 25% of infants tested
released greater than 9% of their blood basophil histamine content in
the presence of cow's milk proteins, indicating a degree or level of latent
anaphylactic sensitivity to these allergens. Approximately 10%
of infants show a considerably higher level of sensitivity (14-63% histamine
release). These findings fulfil an essential tenet of the modified anaphylactic
hypothesis for cot-death.

Guinea-pigs on a normal diet,
but given cow's milk to drink instead of water, very soon became anaphylactically
sensitive to cow's milk and may be fatally shocked following either i.v.
injection or intratracheal inhalation of cow's milk.

Radioallergosorbent test (RAST)
studies showed that IgE antibodies to Dermatophagoides pteronyssinus
(house dust mite), Aspergillus fumigatus and bovine beta-lactoglobulin
were significantly elevated in the sera of infants who died
as a result of the sudden death in infancy syndrome (SDIS). No significant
differences were found in the levels of total IgE, IgA, IgG or IgM in
the sera of SDIS victims or controls. The possible role of hypersensitivity
in the aetiology of SDIS is discussed.

The incidence of 2.5 SDIS cases
per 1,000 live births found in Western Australia is in agreement with
figures reported for other centres. While the age range of SDIS victims
extended from two weeks to 15 months, 57 per cent of deaths occurred in
children of two to four months of age. Boys outnumbered girls 1.6:1. Environmental
factors are implicated in that the majority of deaths occurred in a biphasic
distribution - autumn and late winter months. No significant differences
were observed in total IgE levels in serum from SDIS victims, post mortem
children who died in trauma of known aetiology and live control children
of the same age range. Serum IgE antibodies to D.pteronyssinus were found
in 37% of SDIS victims compared with 7% of matched controls (post mortem
plus live groups). IgE antibodies to beta-lactoglobulin, the major
allergen of cow's milk, appeared with twice the frequency in SDIS vs.
control group but both groups showed a similar incidence of antibodies
to the allergens of Aspergillus fumigatus. The prevalence of IgE antibodies
to D.pteronyssinus in SDIS victims who died in the late winter -- early
spring period was double that found in the group who died in the autumn
period. Sixtyfour percent of the SDIS victims had antibodies to two or
more of the three allergens tested while the control sera were positive
to only one allergen. These results support the hypothesis that anaphylaxis
induced by immediate hypersensitivity to D.pteronyssinus in particular
may be one of the causative factors in SDIS in Western Australia.